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linux/drivers/input/touchscreen/lpc32xx_ts.c
Guenter Roeck 8e1b4d83cf Input: touchscreen - drop unnecessary calls to device_init_wakeup 
Calling device_init_wakeup in the remove function is unnecessary since the
device is going away, and thus won't be able to cause any wakeups under any
circumstances. Besides, the driver cleanup code already handles the
necessary cleanup.

Similarly, disabling wakeup in the probe error path is unnecessary, as is
disabling wakeup in the probe function in the first place.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2017-01-21 23:53:30 -08:00

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/*
* LPC32xx built-in touchscreen driver
*
* Copyright (C) 2010 NXP Semiconductors
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/platform_device.h>
#include <linux/input.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/slab.h>
#include <linux/of.h>
/*
* Touchscreen controller register offsets
*/
#define LPC32XX_TSC_STAT 0x00
#define LPC32XX_TSC_SEL 0x04
#define LPC32XX_TSC_CON 0x08
#define LPC32XX_TSC_FIFO 0x0C
#define LPC32XX_TSC_DTR 0x10
#define LPC32XX_TSC_RTR 0x14
#define LPC32XX_TSC_UTR 0x18
#define LPC32XX_TSC_TTR 0x1C
#define LPC32XX_TSC_DXP 0x20
#define LPC32XX_TSC_MIN_X 0x24
#define LPC32XX_TSC_MAX_X 0x28
#define LPC32XX_TSC_MIN_Y 0x2C
#define LPC32XX_TSC_MAX_Y 0x30
#define LPC32XX_TSC_AUX_UTR 0x34
#define LPC32XX_TSC_AUX_MIN 0x38
#define LPC32XX_TSC_AUX_MAX 0x3C
#define LPC32XX_TSC_STAT_FIFO_OVRRN (1 << 8)
#define LPC32XX_TSC_STAT_FIFO_EMPTY (1 << 7)
#define LPC32XX_TSC_SEL_DEFVAL 0x0284
#define LPC32XX_TSC_ADCCON_IRQ_TO_FIFO_4 (0x1 << 11)
#define LPC32XX_TSC_ADCCON_X_SAMPLE_SIZE(s) ((10 - (s)) << 7)
#define LPC32XX_TSC_ADCCON_Y_SAMPLE_SIZE(s) ((10 - (s)) << 4)
#define LPC32XX_TSC_ADCCON_POWER_UP (1 << 2)
#define LPC32XX_TSC_ADCCON_AUTO_EN (1 << 0)
#define LPC32XX_TSC_FIFO_TS_P_LEVEL (1 << 31)
#define LPC32XX_TSC_FIFO_NORMALIZE_X_VAL(x) (((x) & 0x03FF0000) >> 16)
#define LPC32XX_TSC_FIFO_NORMALIZE_Y_VAL(y) ((y) & 0x000003FF)
#define LPC32XX_TSC_ADCDAT_VALUE_MASK 0x000003FF
#define LPC32XX_TSC_MIN_XY_VAL 0x0
#define LPC32XX_TSC_MAX_XY_VAL 0x3FF
#define MOD_NAME "ts-lpc32xx"
#define tsc_readl(dev, reg) \
__raw_readl((dev)->tsc_base + (reg))
#define tsc_writel(dev, reg, val) \
__raw_writel((val), (dev)->tsc_base + (reg))
struct lpc32xx_tsc {
struct input_dev *dev;
void __iomem *tsc_base;
int irq;
struct clk *clk;
};
static void lpc32xx_fifo_clear(struct lpc32xx_tsc *tsc)
{
while (!(tsc_readl(tsc, LPC32XX_TSC_STAT) &
LPC32XX_TSC_STAT_FIFO_EMPTY))
tsc_readl(tsc, LPC32XX_TSC_FIFO);
}
static irqreturn_t lpc32xx_ts_interrupt(int irq, void *dev_id)
{
u32 tmp, rv[4], xs[4], ys[4];
int idx;
struct lpc32xx_tsc *tsc = dev_id;
struct input_dev *input = tsc->dev;
tmp = tsc_readl(tsc, LPC32XX_TSC_STAT);
if (tmp & LPC32XX_TSC_STAT_FIFO_OVRRN) {
/* FIFO overflow - throw away samples */
lpc32xx_fifo_clear(tsc);
return IRQ_HANDLED;
}
/*
* Gather and normalize 4 samples. Pen-up events may have less
* than 4 samples, but its ok to pop 4 and let the last sample
* pen status check drop the samples.
*/
idx = 0;
while (idx < 4 &&
!(tsc_readl(tsc, LPC32XX_TSC_STAT) &
LPC32XX_TSC_STAT_FIFO_EMPTY)) {
tmp = tsc_readl(tsc, LPC32XX_TSC_FIFO);
xs[idx] = LPC32XX_TSC_ADCDAT_VALUE_MASK -
LPC32XX_TSC_FIFO_NORMALIZE_X_VAL(tmp);
ys[idx] = LPC32XX_TSC_ADCDAT_VALUE_MASK -
LPC32XX_TSC_FIFO_NORMALIZE_Y_VAL(tmp);
rv[idx] = tmp;
idx++;
}
/* Data is only valid if pen is still down in last sample */
if (!(rv[3] & LPC32XX_TSC_FIFO_TS_P_LEVEL) && idx == 4) {
/* Use average of 2nd and 3rd sample for position */
input_report_abs(input, ABS_X, (xs[1] + xs[2]) / 2);
input_report_abs(input, ABS_Y, (ys[1] + ys[2]) / 2);
input_report_key(input, BTN_TOUCH, 1);
} else {
input_report_key(input, BTN_TOUCH, 0);
}
input_sync(input);
return IRQ_HANDLED;
}
static void lpc32xx_stop_tsc(struct lpc32xx_tsc *tsc)
{
/* Disable auto mode */
tsc_writel(tsc, LPC32XX_TSC_CON,
tsc_readl(tsc, LPC32XX_TSC_CON) &
~LPC32XX_TSC_ADCCON_AUTO_EN);
clk_disable_unprepare(tsc->clk);
}
static void lpc32xx_setup_tsc(struct lpc32xx_tsc *tsc)
{
u32 tmp;
clk_prepare_enable(tsc->clk);
tmp = tsc_readl(tsc, LPC32XX_TSC_CON) & ~LPC32XX_TSC_ADCCON_POWER_UP;
/* Set the TSC FIFO depth to 4 samples @ 10-bits per sample (max) */
tmp = LPC32XX_TSC_ADCCON_IRQ_TO_FIFO_4 |
LPC32XX_TSC_ADCCON_X_SAMPLE_SIZE(10) |
LPC32XX_TSC_ADCCON_Y_SAMPLE_SIZE(10);
tsc_writel(tsc, LPC32XX_TSC_CON, tmp);
/* These values are all preset */
tsc_writel(tsc, LPC32XX_TSC_SEL, LPC32XX_TSC_SEL_DEFVAL);
tsc_writel(tsc, LPC32XX_TSC_MIN_X, LPC32XX_TSC_MIN_XY_VAL);
tsc_writel(tsc, LPC32XX_TSC_MAX_X, LPC32XX_TSC_MAX_XY_VAL);
tsc_writel(tsc, LPC32XX_TSC_MIN_Y, LPC32XX_TSC_MIN_XY_VAL);
tsc_writel(tsc, LPC32XX_TSC_MAX_Y, LPC32XX_TSC_MAX_XY_VAL);
/* Aux support is not used */
tsc_writel(tsc, LPC32XX_TSC_AUX_UTR, 0);
tsc_writel(tsc, LPC32XX_TSC_AUX_MIN, 0);
tsc_writel(tsc, LPC32XX_TSC_AUX_MAX, 0);
/*
* Set sample rate to about 240Hz per X/Y pair. A single measurement
* consists of 4 pairs which gives about a 60Hz sample rate based on
* a stable 32768Hz clock source. Values are in clocks.
* Rate is (32768 / (RTR + XCONV + RTR + YCONV + DXP + TTR + UTR) / 4
*/
tsc_writel(tsc, LPC32XX_TSC_RTR, 0x2);
tsc_writel(tsc, LPC32XX_TSC_DTR, 0x2);
tsc_writel(tsc, LPC32XX_TSC_TTR, 0x10);
tsc_writel(tsc, LPC32XX_TSC_DXP, 0x4);
tsc_writel(tsc, LPC32XX_TSC_UTR, 88);
lpc32xx_fifo_clear(tsc);
/* Enable automatic ts event capture */
tsc_writel(tsc, LPC32XX_TSC_CON, tmp | LPC32XX_TSC_ADCCON_AUTO_EN);
}
static int lpc32xx_ts_open(struct input_dev *dev)
{
struct lpc32xx_tsc *tsc = input_get_drvdata(dev);
lpc32xx_setup_tsc(tsc);
return 0;
}
static void lpc32xx_ts_close(struct input_dev *dev)
{
struct lpc32xx_tsc *tsc = input_get_drvdata(dev);
lpc32xx_stop_tsc(tsc);
}
static int lpc32xx_ts_probe(struct platform_device *pdev)
{
struct lpc32xx_tsc *tsc;
struct input_dev *input;
struct resource *res;
resource_size_t size;
int irq;
int error;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res) {
dev_err(&pdev->dev, "Can't get memory resource\n");
return -ENOENT;
}
irq = platform_get_irq(pdev, 0);
if (irq < 0) {
dev_err(&pdev->dev, "Can't get interrupt resource\n");
return irq;
}
tsc = kzalloc(sizeof(*tsc), GFP_KERNEL);
input = input_allocate_device();
if (!tsc || !input) {
dev_err(&pdev->dev, "failed allocating memory\n");
error = -ENOMEM;
goto err_free_mem;
}
tsc->dev = input;
tsc->irq = irq;
size = resource_size(res);
if (!request_mem_region(res->start, size, pdev->name)) {
dev_err(&pdev->dev, "TSC registers are not free\n");
error = -EBUSY;
goto err_free_mem;
}
tsc->tsc_base = ioremap(res->start, size);
if (!tsc->tsc_base) {
dev_err(&pdev->dev, "Can't map memory\n");
error = -ENOMEM;
goto err_release_mem;
}
tsc->clk = clk_get(&pdev->dev, NULL);
if (IS_ERR(tsc->clk)) {
dev_err(&pdev->dev, "failed getting clock\n");
error = PTR_ERR(tsc->clk);
goto err_unmap;
}
input->name = MOD_NAME;
input->phys = "lpc32xx/input0";
input->id.bustype = BUS_HOST;
input->id.vendor = 0x0001;
input->id.product = 0x0002;
input->id.version = 0x0100;
input->dev.parent = &pdev->dev;
input->open = lpc32xx_ts_open;
input->close = lpc32xx_ts_close;
input->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
input->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
input_set_abs_params(input, ABS_X, LPC32XX_TSC_MIN_XY_VAL,
LPC32XX_TSC_MAX_XY_VAL, 0, 0);
input_set_abs_params(input, ABS_Y, LPC32XX_TSC_MIN_XY_VAL,
LPC32XX_TSC_MAX_XY_VAL, 0, 0);
input_set_drvdata(input, tsc);
error = request_irq(tsc->irq, lpc32xx_ts_interrupt,
0, pdev->name, tsc);
if (error) {
dev_err(&pdev->dev, "failed requesting interrupt\n");
goto err_put_clock;
}
error = input_register_device(input);
if (error) {
dev_err(&pdev->dev, "failed registering input device\n");
goto err_free_irq;
}
platform_set_drvdata(pdev, tsc);
device_init_wakeup(&pdev->dev, 1);
return 0;
err_free_irq:
free_irq(tsc->irq, tsc);
err_put_clock:
clk_put(tsc->clk);
err_unmap:
iounmap(tsc->tsc_base);
err_release_mem:
release_mem_region(res->start, size);
err_free_mem:
input_free_device(input);
kfree(tsc);
return error;
}
static int lpc32xx_ts_remove(struct platform_device *pdev)
{
struct lpc32xx_tsc *tsc = platform_get_drvdata(pdev);
struct resource *res;
free_irq(tsc->irq, tsc);
input_unregister_device(tsc->dev);
clk_put(tsc->clk);
iounmap(tsc->tsc_base);
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
release_mem_region(res->start, resource_size(res));
kfree(tsc);
return 0;
}
#ifdef CONFIG_PM
static int lpc32xx_ts_suspend(struct device *dev)
{
struct lpc32xx_tsc *tsc = dev_get_drvdata(dev);
struct input_dev *input = tsc->dev;
/*
* Suspend and resume can be called when the device hasn't been
* enabled. If there are no users that have the device open, then
* avoid calling the TSC stop and start functions as the TSC
* isn't yet clocked.
*/
mutex_lock(&input->mutex);
if (input->users) {
if (device_may_wakeup(dev))
enable_irq_wake(tsc->irq);
else
lpc32xx_stop_tsc(tsc);
}
mutex_unlock(&input->mutex);
return 0;
}
static int lpc32xx_ts_resume(struct device *dev)
{
struct lpc32xx_tsc *tsc = dev_get_drvdata(dev);
struct input_dev *input = tsc->dev;
mutex_lock(&input->mutex);
if (input->users) {
if (device_may_wakeup(dev))
disable_irq_wake(tsc->irq);
else
lpc32xx_setup_tsc(tsc);
}
mutex_unlock(&input->mutex);
return 0;
}
static const struct dev_pm_ops lpc32xx_ts_pm_ops = {
.suspend = lpc32xx_ts_suspend,
.resume = lpc32xx_ts_resume,
};
#define LPC32XX_TS_PM_OPS (&lpc32xx_ts_pm_ops)
#else
#define LPC32XX_TS_PM_OPS NULL
#endif
#ifdef CONFIG_OF
static const struct of_device_id lpc32xx_tsc_of_match[] = {
{ .compatible = "nxp,lpc3220-tsc", },
{ },
};
MODULE_DEVICE_TABLE(of, lpc32xx_tsc_of_match);
#endif
static struct platform_driver lpc32xx_ts_driver = {
.probe = lpc32xx_ts_probe,
.remove = lpc32xx_ts_remove,
.driver = {
.name = MOD_NAME,
.pm = LPC32XX_TS_PM_OPS,
.of_match_table = of_match_ptr(lpc32xx_tsc_of_match),
},
};
module_platform_driver(lpc32xx_ts_driver);
MODULE_AUTHOR("Kevin Wells <kevin.wells@nxp.com");
MODULE_DESCRIPTION("LPC32XX TSC Driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:lpc32xx_ts");
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